Iraqi security forces on Saturday raided the home of a Sunni MP who backed anti-government protesters, sparking clashes that killed his brother and five guards, and arresting him, police said.

"Security forces attacked the residence of MP Ahmed al-Alwani in central Ramadi to arrest him this morning, sparking a battle with his guards with automatic weapons and rocket-propelled grenades," a police major told AFP, referring to a city west of Baghdad.

"Five of Alwani's guards and his brother were killed and eight others wounded, while 10 security forces members were also wounded," the major said.

A police captain confirmed the details of the raid, while a doctor at the Ramadi hospital confirmed the toll.

It was not immediately clear why Alwani was arrested, though he is a well-known supporter of Sunni Arab anti-government protesters camped on a highway near Ramadi, and has frequently spoken at the site.

Protests broke out in Sunni Arab-majority areas of Iraq late last year after the arrest of guards of then-finance minister Rafa al-Essawi, an influential Sunni Arab politician, on terrorism charges.

The arrests were seen by Iraqi Sunnis as just the latest example of the Shiite-led government targeting one of their leaders.

But the demonstrations have tapped into deeper grievances, with Sunnis saying they are both marginalised by the Shiite-led government and unfairly targeted with heavy-handed tactics by security forces.

Iraqi Prime Minister Nuri al-Maliki said this month that the protest site near Ramadi had become a headquarters for Al-Qaeda, and called on legitimate demonstrators to leave.

"I say clearly and honestly that the sit-in site in Anbar has turned into a headquarters for the leadership of Al-Qaeda," Maliki, a Shiite, said in remarks broadcast on state television.

And he called on "those who are with them in this place who refuse sabotage and who have legal or illegal demands... to leave these camps, and leave this place, so that Al-Qaeda stays alone," adding protesters had a "very short period" in which to leave.

If security forces move against the site, it would likely inflame widespread discontent among the minority community and could add to the already rampant violence plaguing the country.

More than 6,700 people have been killed in violence since the beginning of the year, according to AFP figures based on security and medical sources.